A few years back I had the sudden realization that I'd upgraded all my video equipment to HD and then 4k, but hadn't really done anything with my audio. So I went out and got nice equipment (Nice DAC, Headphones, Speakers, Etc).
One of the first things I learned once I could hear music properly was that I had favorite "versions" of different albums. They truly are NOT created equally, but it's not something you can really appreciate on a crummy Bluetooth headset either. Once you can you really start to appreciate the work that folks like your friend do.
I also spent quite a bit of time with some quite well known mastering engineers in a former career - many of them talked about the pressure to produce "loud" masters for CD, but how they were given much more creative freedom for vinyl releases.
Hearing the two masters side by side on some incredible speakers really gave me an appreciation for how different 'versions' of an album can transform the experience of the music.
I/O test for Sans Flex: https://snipboard.io/wXCQq5.jpg
It passes the O0 distinction but not the Il one
Example of a font that passes, Ubuntu: https://fonts.google.com/specimen/Ubuntu?preview.text=10%20I... (custom license but looks similar to GPL in that you can do what you want besides relicensing it as proprietary or removing credits)
Another one, Nunito Sans, using the Open Font License: https://fonts.google.com/specimen/Nunito+Sans?preview.text=1...
IBM Plex Sans is another Open Font License option: https://fonts.google.com/specimen/IBM+Plex+Sans?preview.text... (it has an unusual capital Q style though)
Google Flex Sans supports font-feature-settings: "zero" - but doesn't seem to support lower-case l, upper-case I disambiguation.